This invention relates to pipe arrangements which may be telescoped and applications for such telescoping pipes.
The particular problem to which this invention is directed is to provide a pipe which can be telescoped within another pipe and can be locked at any desired length such that the internal or second pipe cannot be rotated with respect to the external first pipe but a good fluid seal can be provided. One particular application of such a pipe assembly is in the installation of fire sprinklers in commercial or industrial buildings. In such buildings fitted with suspended ceilings there is a necessity to accurately install sprinkler heads in the centers of ceiling tiles for aesthetic purposes.